Critical properties of binary mixtures

Gas-liquid critical pressures of mixtures of octamethylcyclotetrasiloxane with neopentane, 2,3-dimethylbutane, cyclopentane and tetramethylsilane, critical temperatures of octamethylcyclotetra-siloxane + tetramethylsilane mixtures and the vapour pressure of tetramethylsilane near the critical region are reported. The critical temperature and pressure data for these and other mixtures are compared with values calculated from the van der Waals one fluid theory assuming different combining rules and equations of state. The limitations of the criticality condition solutions are discussed briefly.